Aggressive Afterload Lowering to Improve the Right Ventricle: A New Target for Medical Therapy in Pulmonary Arterial Hypertension?

Despite numerous therapeutic advances in pulmonary arterial hypertension, patients continue to suffer high morbidity and mortality, particularly considering a median age of 50 years. This article explores whether early, robust reduction of right ventricular afterload would facilitate substantial improvement in right ventricular function and thus whether afterload reduction should be a treatment goal for pulmonary arterial hypertension. The earliest clinical studies of prostanoid treatment in pulmonary arterial hypertension demonstrated an important link between lowering mean pulmonary arterial pressure (or pulmonary vascular resistance) and improved survival. Subsequent studies of oral monotherapy or sequential combination therapy demonstrated smaller reductions in mean pulmonary arterial pressure and pulmonary vascular resistance. More recently, retrospective reports of initial aggressive prostanoid treatment or initial combination oral and parenteral therapy have shown marked afterload reduction along with significant improvements in right ventricular function. Some data suggest that reaching threshold levels for pressure or resistance (components of right ventricular afterload) may be key to interrupting the self-perpetuating injury of pulmonary vascular disease in pulmonary arterial hypertension and could translate into improved long-term clinical outcomes. Based on these clues, the authors postulate that improved clinical outcomes might be achieved by targeting significant afterload reduction with initial oral combination therapy and early parenteral prostanoids.

Safety and Efficacy of B-Cell Depletion with Rituximab for the Treatment of Systemic Sclerosis-associated Pulmonary Arterial Hypertension: A Multicenter, Double-Blind, Randomized, Placebo-controlled Trial.

Rationale: Systemic sclerosis (SSc)-pulmonary arterial hypertension (PAH) is one of the most prevalent and deadly forms of PAH. B cells may contribute to SSc pathogenesis. Objectives: We investigated the safety and efficacy of B-cell depletion for SSc-PAH. Methods: In an NIH-sponsored, multicenter, double-blinded, randomized, placebo-controlled, proof-of-concept trial, 57 patients with SSc-PAH on stable-dose standard medical therapy received two infusions of 1,000 mg rituximab or placebo administered 2 weeks apart. The primary outcome measure was the change in 6-minute-walk distance (6MWD) at 24 weeks. Secondary endpoints included safety and invasive hemodynamics. We applied a machine learning approach to predict drug responsiveness. Measurements and Main Results: We randomized 57 subjects from 2010 to 2018. In the primary analysis, using data through Week 24, the adjusted mean change in 6MWD at 24 weeks favored the treatment arm but did not reach statistical significance (23.6 ± 11.1 m vs. 0.5 ± 9.7 m; P = 0.12). Although a negative study, when data through Week 48 were also considered, the estimated change in 6MWD at Week 24 was 25.5 ± 8.8 m for rituximab and 0.4 ± 7.4 m for placebo (P = 0.03). Rituximab treatment appeared to be safe and well tolerated. Low levels of RF (rheumatoid factor), IL-12, and IL-17 were sensitive and specific as favorable predictors of a rituximab response as measured by an improved 6MWD (receiver operating characteristic area under the curve, 0.88-0.95). Conclusions: B-cell depletion therapy is a potentially effective and safe adjuvant treatment for SSc-PAH. Future studies in these patients can confirm whether the identified biomarkers predict rituximab responsiveness. Clinical trial registered with www.clinicaltrails.gov (NCT01086540).

Combination Therapy with Oral Treprostinil for Pulmonary Arterial Hypertension. A Double-Blind Placebo-controlled Clinical Trial.

Rationale: Oral treprostinil improves exercise capacity in patients with pulmonary arterial hypertension (PAH), but the effect on clinical outcomes was unknown.Objectives: To evaluate the effect of oral treprostinil compared with placebo on time to first adjudicated clinical worsening event in participants with PAH who recently began approved oral monotherapy.Methods: In this event-driven, double-blind study, we randomly allocated 690 participants (1:1 ratio) with PAH to receive placebo or oral treprostinil extended-release tablets three times daily. Eligible participants were using approved oral monotherapy for over 30 days before randomization and had a 6-minute-walk distance 150 m or greater. The primary endpoint was the time to first adjudicated clinical worsening event: death; hospitalization due to worsening PAH; initiation of inhaled or parenteral prostacyclin therapy; disease progression; or unsatisfactory long-term clinical response.Measurements and Main Results: Clinical worsening occurred in 26% of the oral treprostinil group compared with 36% of placebo participants (hazard ratio, 0.74; 95% confidence interval, 0.56-0.97; P = 0.028). Key measures of disease status, including functional class, Borg dyspnea score, and N-terminal pro-brain natriuretic peptide, all favored oral treprostinil treatment at Week 24 and beyond. A noninvasive risk stratification analysis demonstrated that oral treprostinil-assigned participants had a substantially higher mortality risk at baseline but achieved a lower risk profile from Study Weeks 12-60. The most common adverse events in the oral treprostinil group were headache, diarrhea, flushing, nausea, and vomiting.Conclusions: In participants with PAH, addition of oral treprostinil to approved oral monotherapy reduced the risk of clinical worsening.Clinical trial registered with www.clinicaltrials.gov (NCT01560624).

Combination therapy improves vascular volume in female rats with pulmonary hypertension.

Pulmonary arterial hypertension (PAH) is a female predominant disease in which progressive vascular remodeling and vasoconstriction result in right ventricular (RV) failure and death. Most PAH patients utilize multiple therapies. In contrast, the majority of preclinical therapeutic studies are performed in male rats with a single novel drug often markedly reversing disease in the model. We sought to differentiate single drug therapy from combination therapy in female rats with severe disease. One week after left pneumonectomy, we induced PH in young female Sprague-Dawley rats with an injection of monocrotaline (45 mg/kg). Female rats were then randomized to receive combination therapy (ambrisentan plus tadalafil), ambrisentan monotherapy, tadalafil monotherapy, or vehicle. We measured RV size and function on two serial echocardiograms during the development of disease. We measured RV systolic pressure (RVSP) invasively at day 28 after monocrotaline before analyzing the vascular volume with microcomputed tomography (microCT) of the right middle lobe. RVSP was significantly lower in female rats treated with combination therapy, and combination therapy resulted in increased small vessel volume density measured by microCT compared with untreated rats. Combination-treated rats had the smallest RV end-diastolic diameter on echocardiogram as compared with the other groups. In summary, we report a female model of pulmonary hypertension that can distinguish between one and two drug therapies; this model may facilitate better preclinical drug testing for novel compounds.

Clinical outcomes stratified by baseline functional class after initial combination therapy for pulmonary arterial hypertension.

BACKGROUND: Initial combination therapy with ambrisentan and tadalafil reduced the risk of clinical failure events for treatment-naïve participants with pulmonary arterial hypertension (PAH) as compared to monotherapy. Previous studies in PAH have demonstrated greater treatment benefits in more symptomatic participants. METHODS: AMBITION was an event-driven, double-blind study in which participants were randomized 2:1:1 to once-daily initial combination therapy with ambrisentan 10 mg plus tadalafil 40 mg, ambrisentan 10 mg plus placebo, or tadalafil 40 mg plus placebo. In this pre-specified subgroup analysis, we compared the efficacy data between those with functional class (FC) II vs. FC III symptoms at baseline. RESULTS: This analysis included 500 participants in the previously defined primary analysis set (n = 155 FC II, n = 345 FC III). Comparing combination therapy to pooled monotherapy, the risk of clinical failure events was reduced by 79% (hazard ratio, 0.21 [95% confidence interval: 0.071, 0.63]) for FC II patients and 42% (hazard ratio, 0.58 [95% confidence interval: 0.39, 0.86]) for FC III patients. In a post-hoc analysis, the risk of first hospitalization for worsening PAH was also reduced by combination therapy, particularly for FC II patients (0 combination vs. 11 [14%] pooled monotherapy). Adverse events were frequent but comparable between the subgroups. CONCLUSIONS: Treatment benefit from initial combination therapy appeared at least as great for FC II as for FC III participants. Hospitalizations for worsening PAH were not observed in FC II participants assigned to combination. The present data support an initial combination strategy for newly diagnosed patients even when symptoms are less severe. Funded by Gilead Sciences, Inc. and GlaxoSmithKline; AMBITION ClinicalTrials.gov number, NCT01178073.

Initial Use of Ambrisentan plus Tadalafil in Pulmonary Arterial Hypertension.

BACKGROUND: Data on the effect of initial combination therapy with ambrisentan and tadalafil on long-term outcomes in patients with pulmonary arterial hypertension are scarce. METHODS: In this event-driven, double-blind study, we randomly assigned, in a 2:1:1 ratio, participants with World Health Organization functional class II or III symptoms of pulmonary arterial hypertension who had not previously received treatment to receive initial combination therapy with 10 mg of ambrisentan plus 40 mg of tadalafil (combination-therapy group), 10 mg of ambrisentan plus placebo (ambrisentan-monotherapy group), or 40 mg of tadalafil plus placebo (tadalafil-monotherapy group), all administered once daily. The primary end point in a time-to-event analysis was the first event of clinical failure, which was defined as the first occurrence of a composite of death, hospitalization for worsening pulmonary arterial hypertension, disease progression, or unsatisfactory long-term clinical response. RESULTS: The primary analysis included 500 participants; 253 were assigned to the combination-therapy group, 126 to the ambrisentan-monotherapy group, and 121 to the tadalafil-monotherapy group. A primary end-point event occurred in 18%, 34%, and 28% of the participants in these groups, respectively, and in 31% of the pooled-monotherapy group (the two monotherapy groups combined). The hazard ratio for the primary end point in the combination-therapy group versus the pooled-monotherapy group was 0.50 (95% confidence interval [CI], 0.35 to 0.72; P<0.001). At week 24, the combination-therapy group had greater reductions from baseline in N-terminal pro-brain natriuretic peptide levels than did the pooled-monotherapy group (mean change, -67.2% vs. -50.4%; P<0.001), as well as a higher percentage of patients with a satisfactory clinical response (39% vs. 29%; odds ratio, 1.56 [95% CI, 1.05 to 2.32]; P=0.03) and a greater improvement in the 6-minute walk distance (median change from baseline, 48.98 m vs. 23.80 m; P<0.001). The adverse events that occurred more frequently in the combination-therapy group than in either monotherapy group included peripheral edema, headache, nasal congestion, and anemia. CONCLUSIONS: Among participants with pulmonary arterial hypertension who had not received previous treatment, initial combination therapy with ambrisentan and tadalafil resulted in a significantly lower risk of clinical-failure events than the risk with ambrisentan or tadalafil monotherapy. (Funded by Gilead Sciences and GlaxoSmithKline; AMBITION ClinicalTrials.gov number, NCT01178073.).

Low dose monocrotaline causes a selective pulmonary vascular lesion in male and female pneumonectomized rats.

Purpose/Aim: Low doses (30-80 mg/kg) of monocrotaline are commonly used to create experimental models of pulmonary hypertension in rats. At these doses, monocrotaline causes pulmonary endothelial apoptosis and acute lung injury which ultimately results in pulmonary vascular disease. Higher doses of monocrotaline (300 mg/kg) are known to create severe liver injury, but previous investigations with lower doses have not reported histology in other organs to determine whether the vascular injury with monocrotaline is pulmonary-selective or generalized. MATERIALS AND METHODS: We therefore sought to determine whether monocrotaline caused extra-pulmonary injury at doses commonly used in pulmonary hypertension studies. We performed left pneumonectomy on young male and female rats before administering 50-60 mg/kg monocrotaline 7 days later. We monitored serum chemistry and urine dipsticks during the first 3 weeks while the animals developed pulmonary hypertension. After 3 weeks, we sacrificed animals and stained the lungs and highly vascular visceral organs (kidney, liver, and spleen) for elastin to evaluate the degree of vascular injury and remodeling. RESULTS: We did not observe proteinuria or significant transaminitis over the 3 weeks following monocrotaline. As previously published, monocrotaline caused severe pulmonary vascular disease with neointimal lesions and medial hypertrophy. We did not identify significant large or small arterial damage in the kidneys, liver, or spleen. Two external veterinary pathologists did not identify histopathology in the kidneys, liver, or spleen of these rats. CONCLUSIONS: We conclude that 50-60 mg/kg of monocrotaline causes a selective pulmonary vascular lesion and that male and female rats have little non-pulmonary damage over 3 weeks at these doses of monocrotaline.

Hepatic Shunting of Eggs and Pulmonary Vascular Remodeling in Bmpr2(+/-) Mice with Schistosomiasis.

RATIONALE: Schistosomiasis is a major cause of pulmonary arterial hypertension (PAH). Mutations in the bone morphogenetic protein type-II receptor (BMPR-II) are the commonest genetic cause of PAH. OBJECTIVES: To determine whether Bmpr2(+/-) mice are more susceptible to schistosomiasis-induced pulmonary vascular remodeling. METHODS: Wild-type (WT) and Bmpr2(+/-) mice were infected percutaneously with Schistosoma mansoni. At 17 weeks postinfection, right ventricular systolic pressure and liver and lung egg counts were measured. Serum, lung and liver cytokine, pulmonary vascular remodeling, and liver histology were assessed. MEASUREMENTS AND MAIN RESULTS: By 17 weeks postinfection, there was a significant increase in pulmonary vascular remodeling in infected mice. This was greater in Bmpr2(+/-) mice and was associated with an increase in egg deposition and cytokine expression, which induced pulmonary arterial smooth muscle cell proliferation, in the lungs of these mice. Interestingly, Bmpr2(+/-) mice demonstrated dilatation of the hepatic central vein at baseline and postinfection, compared with WT. Bmpr2(+/-) mice also showed significant dilatation of the liver sinusoids and an increase in inflammatory cells surrounding the central hepatic vein, compared with WT. This is consistent with an increase in the transhepatic passage of eggs. CONCLUSIONS: This study has shown that levels of BMPR-II expression modify the pulmonary vascular response to chronic schistosomiasis. The likely mechanism involves the increased passage of eggs to the lungs, caused by altered diameter of the hepatic veins and sinusoids in Bmpr2(+/-) mice. Genetically determined differences in the remodeling of hepatic vessels may represent a new risk factor for PAH associated with schistosomiasis.

Efficacy and safety of oral treprostinil monotherapy for the treatment of pulmonary arterial hypertension: a randomized, controlled trial.

BACKGROUND: Pulmonary arterial hypertension (PAH) is a progressive, fatal disease with no cure. Parenteral and inhaled prostacyclin analogue therapies are effective for the treatment of PAH, but complicated administration requirements can limit the use of these therapies in patients with less severe disease. This study was designed to evaluate the safety and efficacy of the oral prostacyclin analogue treprostinil diolamine as initial treatment for de novo PAH. METHODS AND RESULTS: Three hundred forty-nine patients (intent-to-treat population) not receiving endothelin receptor antagonist or phosphodiesterase type-5 inhibitor background therapy were randomized (treprostinil, n=233; placebo, n=116). The primary analysis population (modified intent-to-treat) included 228 patients (treprostinil, n=151; placebo, n=77) with access to 0.25-mg treprostinil tablets at randomization. The primary end point was change from baseline in 6-minute walk distance at week 12. Secondary end points included Borg dyspnea index, clinical worsening, and symptoms of PAH. The week 12 treatment effect for 6-minute walk distance (modified intent-to-treat population) was 23.0 m (P=0.0125). For the intent-to-treat population, 6-minute walk distance improvements were observed at peak (26.0 m; P=0.0001) and trough (17.0 m; P=0.0025) plasma study drug concentrations. Other than an improvement in the combined 6-minute walk distance/Borg dyspnea score, there were no significant changes in secondary end points. Oral treprostinil therapy was generally well tolerated; the most common adverse events (intent-to-treat) were headache (69%), nausea (39%), diarrhea (37%), and pain in jaw (25%). CONCLUSIONS: Oral treprostinil improves exercise capacity in PAH patients not receiving other treatment. Oral treprostinil could provide a convenient, first-line prostacyclin treatment option for PAH patients not requiring more intensive therapy. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00325403.

Cardiac effort and 6-min walk distance correlate with stroke volume measured by cardiac magnetic resonance imaging.

Right ventricular (RV) dysfunction in pulmonary arterial hypertension (PAH) is associated with poor outcomes. Cardiac magnetic resonance imaging (cMRI) is the gold standard for volumetric assessment, and few reports have correlated 6-min walk distance (6MWD) and cMRI parameters in PAH. Cardiac Effort, (the number of heart beats used during 6-min walk test)/(6MWD), incorporates physiologic changes into walk distance and has been associated with stroke volume (SV) measured by nuclear imaging and indirect Fick. Here, we aimed to interrogate the relationship of Cardiac Effort and 6MWD with SV measured by the gold standard, cMRI. This was a single-center, observational, prospective study in Group 1 PAH patients. Subjects completed 6-min walk with heart rate monitoring (Cardiac Effort) and cMRI within 24 h. cMRI was correlated to Cardiac Effort and 6MWD using Spearman Correlation Coefficient. Twenty-five participants with a wide range of RV function completed both cMRI and Cardiac Effort. There was a strong correlation between left ventricle SV index and both Cardiac Effort (r = -0.70, p = 0.0001) and 6MWD (r = 0.67, p = 0.0002). Cardiac Effort and 6MWD were statistically separated in patients at prognostically significant thresholds of left ventricle SV index (>31 ml/m2), RV Ejection Fraction (>35%), and SV/End Systolic Volume ( > 0.53). Cardiac Effort and 6MWD are noninvasive ways to gain insight into those with impaired SV. 6MWD may correlate better with SV than previously thought and heart rate monitoring provides physiologic context to the walk distance obtained.

Utility of factor D and other alternative complement factors as biomarkers in systemic sclerosis-associated pulmonary arterial hypertension (SSc-PAH).

BACKGROUND: Activation of the complement cascade is thought to play a role in scleroderma vasculopathy. We previously showed that complement factor D was elevated in patients with limited cutaneous SSc and pulmonary arterial hypertension (PAH). In this study, we sought to assess multiple relevant components of the complement cascade to determine if they are altered in SSc-PAH, as well as their potential utility as biomarkers of disease severity and progression. METHODS: Complement components (n = 14) were measured using multiplex assays in 156 patients with SSc-PAH from a multi-site repository and were compared to 33 patients with SSc without PAH, and 40 healthy controls. Data were evaluated for correlations between complement levels, right heart catheterization measures, and clinical endpoints including 6-minute walk distance. To assess complement longitudinally, serum complement levels were assayed at 0, 4, 12, 24, 36 and 48 weeks in 52 SSc-PAH patients who participated in a prior clinical trial. RESULTS: We found that factor D was significantly elevated in SSc-PAH compared to SSc without PAH (p < 0.0001) and was highly sensitive and specific for SSc-PAH (AUC=0.82, p < 0.001). In SSc-PAH patients, alterations in factor H, C4, and factor D were associated with measures of PAH disease severity including right heart catheterization measurements (cardiac output, right atrial pressure, and VO2 max), survival, and 6-minute walk distance. No significant changes in complement levels or clinical associations were seen over time or associated with treatment in the longitudinal clinical trial study. CONCLUSION: Our work confirms prior studies demonstrating a role for complement activation in SSc vascular disease and elevations of factor D in a large SSc-PAH population. Further, factor H and other complement factors are associated with severity of PAH including mortality. Taken together, these findings suggest that the alternative complement pathway plays a role in SSc-PAH pathogenesis and may serve as a biomarker to inform diagnosis and prognosis.

Oral Treprostinil is Associated with Improved Survival in FREEDOM-EV and its Open-Label Extension.

INTRODUCTION: In the event-driven FREEDOM-EV trial, oral treprostinil delayed clinical worsening in patients with pulmonary arterial hypertension (PAH). Open-label extension studies offer additional data about tolerability, efficacy, and survival, especially for those initially assigned placebo. The aim of the current study was to determine if oral treprostinil changed survival when considering the parent and extension study, if treprostinil provides functional benefits for participants initially assigned to placebo, and if the benefits observed for those treated with treprostinil were durable. METHODS: Both active and placebo participants from FREEDOM-EV could enroll in the FREEDOM-EV open-label extension (OLE) study after experiencing an investigator-assessed clinical worsening event or after parent study closure. All participants in the OLE were offered open-label oral treprostinil. Previously assigned placebo participants titrated to maximally tolerated doses; previously assigned treprostinil participants continued dose titration. We repeated assessments including functional class and 6-min walk distance (6MWD) at 12-week intervals and measured N-terminal pro-brain natriuretic peptide (NT-proBNP) at week 48. Survival was estimated by Kaplan-Meier analysis, and we estimated hazard ratio (HR) using Cox proportional hazards. RESULTS: Of 690 FREEDOM-EV participants, 470 enrolled in the OLE; vital status was available for 89% of initial Freedom-EV participants. When considering the combined parent and open-label data, initial assignment to oral treprostinil reduced mortality (HR 0.64, 95% confidence interval 0.46-0.91, p = 0.013); absolute risk reduction was 9%. Participants randomized to placebo who initiated oral treprostinil after clinical worsening and tolerated treatment through week 48 demonstrated favorable shifts in functional class (p < 0.0001), 6MWD improvements of + 84 m (p < 0.0001), and a reduction in NT-proBNP of - 778 pg/mL (p = 0.02), compared to OLE baseline. Modest trends toward benefit were measured for those initially assigned placebo who did not have clinical worsening, and 132/144 (92%) of treprostinil assigned participants without clinical worsening remained on drug at week 48 in the OLE study. Adverse events were consistent with FREEDOM-EV. CONCLUSION: Initial treprostinil assignment improved survival in the entire data set; those who began treprostinil after a clinical worsening in the placebo arm and tolerated drug to week 48 enjoyed substantial functional gains. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT01560637.

Application of REVEAL Lite 2 and COMPERA 2.0 risk scores to patients with pulmonary arterial hypertension switching to riociguat in the REPLACE study.

In Riociguat rEplacing PDE5i therapy evaLuated Against Continued PDE5i thErapy (REPLACE) (NCT02891850), improvements in risk status were observed in patients with pulmonary arterial hypertension (PAH) at intermediate risk switching to riociguat versus continuing phosphodiesterase-5 inhibitors (PDE5i). This post hoc study applied the Registry to Evaluate Early and Long-Term PAH Disease Management (REVEAL) Lite 2 and Comparative Prospective Registry of Newly Initiated Therapies for Pulmonary (COMPERA) 2.0 risk-assessment tools to REPLACE to investigate the impact of baseline risk status on clinical improvement. The proportions of riociguat- and PDE5i-treated patients achieving the primary end-point at REVEAL Lite 2 low, intermediate, and high baseline risk reflected the overall population. Proportions of riociguat-treated patients achieving the primary end-point were comparable between the COMPERA 2.0 intermediate-low risk (39%) and intermediate-high risk (43%) groups. Our findings show that patients in REPLACE achieved clinical improvement by switching from PDE5i to riociguat across all COMPERA 2.0 and most REVEAL Lite 2 baseline risk strata.

Gaps in evidence in the treatment of prevalent patients with pulmonary arterial hypertension at intermediate risk: An expert consensus.

Despite the innovations introduced in the 2022 European Society of Cardiology/European Respiratory Society Guidelines on Pulmonary Hypertension, risk discrimination and management of pulmonary arterial hypertension (PAH) patients at intermediate risk still represents a grey zone. Additionally, clinical evidence derived from currently available studies is limited. This expert panel survey intends to aid physicians in choosing the best therapeutic strategy for patients at intermediate risk despite ongoing oral therapy. An expert panel of 24 physicians, specialized in cardiology and/or pulmonology with expertise in handling all drugs available for the treatment of PAH participated in the survey. All potential therapeutic options for patients at intermediate risk were explored and analyzed to produce graded consensus statements regarding: the switch from endothelin receptor antagonist (ERA) or phosphodiesterase 5 inhibitor (PDE5i) to another oral drug of the same class; the addition of a drug targeting the prostacyclin pathway administered by different routes; the switch from PDE5i to riociguat.

Pharmacokinetics of oral treprostinil sustained release tablets during chronic administration to patients with pulmonary arterial hypertension.

Pulmonary arterial hypertension (PAH) is a progressive vascular disease that ultimately leads to right ventricular failure and death. Treprostinil diolamine is an oral prostacyclin analogue; sustained release tablets of oral treprostinil are currently being evaluated for efficacy and safety as a potential therapy in patients with PAH. Previous attempts at developing an oral prostanoid have been limited by rapid absorption and short plasma half-life; thus, the aim of this study was to characterize the pharmacokinetic profile of treprostinil diolamine in PAH patients after chronic dosing. The study enrolled 74 PAH patients who had been taking treprostinil diolamine for a minimum of 4 weeks (range: 0.5-16 mg). We collected plasma samples over 12 hours and estimated pharmacokinetic parameters using noncompartmental methods. Seventy patients had complete data. After chronic twice-daily oral dosing of treprostinil diolamine, mean area under the curve (AUC0-12) of treprostinil increased from 5244 to 20,4086 pg·hr-·mL- and mean maximum observed plasma concentration (Cmax) increased from 1383 to 33588 pg/mL. The apparent clearance (CL/F) was similar across all doses, indicating a linear dose-exposure relationship after twice-daily dosing. We conclude that twice-daily oral treprostinil provides sustained and proportional treprostinil concentrations over a wide range of doses during chronic administration to PAH patients.

Peak steps: Capacity for activity improves after adding approved therapy in pulmonary arterial hypertension.

Pulmonary arterial hypertension (PAH) patients have low activity. Activity intensity or duration could be a measure of clinical status or improvement. We aimed to determine whether standard or novel actigraphy measures could detect increases in activity after adding therapy. This was a prospective, single-center observational study evaluating activity after adding therapy in Group 1 PAH; we also report a validation cohort. For our study, two different accelerometers were used, a wrist (ActiGraph) and chest (MC10) device. Patients were analyzed in two groups, Treatment Intensification (TI, adding therapy) or Stable. Both groups had baseline monitoring periods of 7 days; the TI group had follow-up at 3 months, while Stables had follow-up within 4 weeks to assess stability. Activity time and steps were reported from both devices' proprietary algorithms. In ActiGraph only, steps in 1-min intervals throughout the day were ranked (not necessarily contiguous). Average values for each week were calculated and compared using nonparametric testing. Thirty patients had paired data (11 Stable and 19 TI). There was no between-group difference at baseline; we did not observe therapy-associated changes on average daily steps or activity time/intensity. The top 5 min of steps (capacity) increased after adding therapy; there was no difference in the stable group. This key finding was validated in a previously reported randomized trial studying a behavioral intervention to increase exercise. Total daily activity metrics are influenced by both disease and non-disease factors, making therapy-associated change difficult to detect. Peak minute steps were a treatment-responsive marker in both a pharmacologic and training intervention.

Evaluation of Clinical Recovery After Surgical Treatment for Hand Ischemia From Vasospastic and Occlusive Disease Using PROMIS.

BACKGROUND: There is a paucity of literature describing the recovery trajectory after surgery for upper extremity ischemia. Using Patient-Reported Outcomes Measurement Information System (PROMIS) Physical Function (PF), Upper Extremity (UE), Pain Interference (PI), and Depression domains, we aimed to describe the postoperative recovery of such patients. METHODS: We queried our PROMIS database for patients undergoing surgery for vasospastic or occlusive disease over a 4.5-year period. Inclusion criteria were preoperative, early (average 3 weeks) and late (average 6 months) postoperative PROMIS PF and/or UE, PI, and Depression scores. The change in PROMIS scores was calculated for each time point. Changes in PROMIS scores were compared with minimal clinically important difference estimates. RESULTS: We identified 13 patients undergoing 13 surgical interventions that met inclusion criteria. More than one-half of our patients were men (n = 7 [54%]), and more than one-half of the surgeries (n = 7 [54%]) were for isolated occlusive diagnoses, with the remainder for vasospastic disease. At short-term postoperative follow-up, the change in PROMIS PF, UE, PI, and Depression scores was -6.34 (SD: 9.13), -6.81 (SD: 9.61), 3.16 (SD: 5.78), and -3.05 (SD: 8.37), respectively. At mid-term postoperative follow-up, the change in PROMIS PF, UE, PI, and Depression scores was 4.45 (SD: 10.33), 8.04 (SD: 13.84), -7.03 (SD: 7.06), and -12.27 (SD: 10.85), respectively. CONCLUSIONS: Our findings suggest patients undergoing surgical treatment for upper extremity ischemia experience a worsening of functional symptoms initially, as expected, followed by notable improvement.